Reefwander
Reefwander
Full calendar

Destinations at their peak each month

  1. Jan167
  2. Feb183
  3. Mar192
  4. Apr216
  5. May186
  6. Jun272
  7. Jul307
  8. Aug313
  9. Sep296
  10. Oct180
  11. Nov119
  12. Dec145

Americas

Europe, Africa & Middle East

Indo-Pacific

October 2026 · 180 at their peak

Where to dive, month by month

180 at their peak in October357 goodthe restOpen October on the map →

The right month for Komodo is the wrong one for Raja Ampat, and every operator's website says come now. Reefwander rates 732 dive destinations for all twelve months of the year from published sources, so you can start from when you can travel, see where the sea is at its best, and read the named dive sites underneath before you book.

Where to dive in OctoberOpen the map
Destinations
732
Dive sites
4,685
Guides
64
Regions
15

Where the sea is at its best in October

180 dive destinations are at their peak in October, with another 357 in good shape. The strongest regions are Coral Triangle, Mediterranean, East Asia; water runs from 1 °C to 32 °C (34–90 °F).

All 180 at their peak in October →

Warm-water pick

New Ireland & Kavieng

Papua New Guinea

The New Hanover trips run from May to October; rain from late December to March and North Pacific swell from November to April mark the rest of the year.

29–32°C · 84–90°Fintermediate

Clear-water pick

Christmas Island

Australia

October to December brings the clearest water; August and September bring upwellings and lower visibility; from November to April swell can roughen the north side.

26–29°C · 79–84°Fvis 60 m · 197 ftintermediate

Cold-water pick

Oslofjord — Nesodden & Fornebu

Norway

Autumn and winter are usually the high season; September to March has the clearest water, April to October the warmest.

3–18°C · 37–64°Fvis 25 m · 82 ftintermediate

Coral Triangle

Tulamben

Indonesia

Diveable all year. April to July and October to November give the calmest, clearest water; December to March is the rainy season, with more run-off and fewer divers.

26–29°C · 79–84°Fvis 25 m · 82 ftbeginner

Mediterranean

Crete

Greece

April to November is the season, warmest from July to September; the summer meltemi can blow out the exposed north-coast sites for a day or two at a time.

16–27°C · 61–81°Fvis 30 m · 100 ftbeginner

Red Sea & Gulf of Aden

Sharm El Sheikh — Ras Mohammed

Egypt

Hammerhead sightings at Tiran peak June–September; winter winds can make Tiran crossings choppier.

21–29°C · 70–84°Fvis 35 m · 115 ftintermediate

Travelling another month? Pick it here, or see the whole year.

Explore by region

Fifteen regions, from the Caribbean to the cold water. Each region page compares its destinations on season, temperature, visibility and the animals you can expect.

Or by what you're after

Start from the animal or the kind of diving you want. Each tile opens the list already filtered, and the list then narrows by month, difficulty and how you get in the water.

Reefwander on YouTube

One destination, one animal or one number per film, a minute or so each, narrated over our own maps and charts. Press play and the video loads here.

All videos on YouTube →

From the Logbook

Long-form guides built on the same data as the map: where the animals are by month, what the physics says about your limits, and which entries are worth the trip. Every claim is linked to its source.

All 64 guides →

Ocean science

Hearing underwater: why sound has no direction

A boat that is everywhere and nowhere, a whale you never see, a crackle like frying fat, and your own breathing over the top of it all. Underwater hearing is not a muffled version of hearing in air — it is a different sense, run through the bones of your head. Here is the physics, with the numbers computed.

1 October 2026 · 14 min read

Big animals

Where to see reef sharks on your first dives

14 min readOcean science

Why things look bigger underwater

12 min readCold water

Ice diving: how it works and where to go

12 min read

Read by theme

The guides filed as reading lists, in the order they build on each other. Start anywhere; each one stands on its own.

  1. The physics of a dive

    Every limit on a dive computed from the model behind it: depth, gas, stops, the flight home.

    9 guides
    1. 1How deep can you scuba dive?13 min
    2. 2How a dive computer calculates no-stop time10 min
    3. 3Do you need a safety stop? What it buys you11 min
    4. 4How long should a surface interval be?8 min
    5. 5What is decompression sickness (the bends)?18 min
    6. 6Gas density: why deep air gets hard to breathe8 min
    7. 7Why is 1.4 bar the oxygen limit in diving?13 min
    8. 8How long to wait before flying after diving8 min
    9. 9Altitude diving: how the rules change7 min

  2. Your body underwater

    What pressure, cold water and the reef itself do to a diver, and what to do about each.

    7 guides
    1. 1Why your ears hurt diving, and how to stop it8 min
    2. 2Why do you pee when diving, and tire after?12 min
    3. 3Why you get cold diving, even in a wetsuit8 min
    4. 4What stings you underwater, and how to avoid it8 min
    5. 5Wetsuit thickness by water temperature11 min
    6. 6How much weight do you need to dive?8 min
    7. 7How long does a tank of air last?9 min

  3. Big animals, month by month

    Where the sharks, rays, whales and seals are reliably met, and the months each place works.

    11 guides
    1. 1When and where to dive with hammerheads16 min
    2. 2Where to dive with manta rays, month by month8 min
    3. 3Where to dive with whale sharks, month by month16 min
    4. 4Where to dive with tiger, bull and white sharks14 min
    5. 5Where to see reef sharks on your first dives14 min
    6. 6Where to dive with oceanic whitetip sharks11 min
    7. 7Malapascua thresher sharks: Monad or Kimud?11 min
    8. 8Sunfish diving: where and when to see a mola11 min
    9. 9Where can you legally swim with whales?14 min
    10. 10Where to dive with seals and sea lions17 min
    11. 11Where to dive with sea turtles15 min

  4. How the sea behaves

    Colour, light, sound, layers, tides and swell: the ocean physics you can feel on a dive.

    10 guides
    1. 1Why is the sea blue? Water filters out red7 min
    2. 2Why is some sea green instead of blue?8 min
    3. 3How far you can see underwater12 min
    4. 4Why things look bigger underwater12 min
    5. 5Hearing underwater: why sound has no direction14 min
    6. 6What are thermoclines and haloclines?8 min
    7. 7Bioluminescence: why the sea glows at night7 min
    8. 8What is surge in diving, and how deep it goes8 min
    9. 9When is slack water? Tides for divers7 min
    10. 10When does coral spawn? The moon's calendar10 min

  5. Wrecks

    From a first shallow hull to the trimix ground past 60 m, sorted by the depth each one asks for.

    5 guides
    1. 1Your first wreck dive: what to expect and where6 min
    2. 2Ships sunk on purpose, and where to dive them14 min
    3. 3WWII wrecks you can dive, by theatre7 min
    4. 4Deep wreck diving: where recreational stops8 min
    5. 5Malta and Gozo wreck diving, by depth and month10 min

  6. Kinds of diving

    The best places for each way of diving, and what each one asks of you.

    15 guides
    1. 1The best shore dives in the world8 min
    2. 2The best wall dives in the world11 min
    3. 3The best muck diving in the world6 min
    4. 4Night diving: the best night dives in the world12 min
    5. 5Blackwater diving: what it is and where to go13 min
    6. 6Frogfish: species, behaviour and where to dive12 min
    7. 7Nudibranchs: species, habits and where to dive13 min
    8. 8Cavern and cenote diving without cave training8 min
    9. 9Cave diving: what it takes and where to go12 min
    10. 10What is a blue hole, and what's down there?13 min
    11. 11Drift diving: how to read and ride a current8 min
    12. 12Cold-water diving: is it worth the drysuit?8 min
    13. 13Ice diving: how it works and where to go12 min
    14. 14Kelp forest diving, and where it still grows13 min
    15. 15Freshwater diving: lakes, springs and quarries15 min

  7. Gear, gas and planning a trip

    What the kit changes, which gas to breathe, and how to choose and pay for the trip itself.

    7 guides
    1. 1Air, nitrox or trimix: which gas, and when?15 min
    2. 2How a rebreather works, and what it buys you8 min
    3. 3DPV diving: what an underwater scooter changes10 min
    4. 4Liveaboard vs resort diving: which suits you?6 min
    5. 5Cheapest places to scuba dive, and the catch15 min
    6. 6Where to dive in every month of the year14 min
    7. 7Where to dive in December10 min

How Reefwander is made

Written from sources

Every dive site page is written from published material: operator briefings, park notices, wreck registers, scientific papers. The sources are listed on the page, so a depth or a season can be checked rather than trusted. Where sources disagree, the page says so.

Rated month by month

Each month at each destination is marked peak, good, fair or off-season from the published season, water temperature and visibility for that place, not from a forecast. The month pages, the list and the map all read the same twelve marks.

Built on open data

Seabed depth from NOAA, coral reef extent from the Allen Coral Atlas, coastlines and marine protected areas from OpenStreetMap, silhouettes from PhyloPic, and photographs under Creative Commons with every photographer credited and linked.

Reefwander is independent: no operator, agency or certification body owns it, and no place on it is a paid listing. Read how the site is put together, orwrite in with a correction or a place we are missing.